JPH0729552B2 - Four-wheel drive vehicle for agriculture - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural four-wheel drive vehicle such as a speed sprayer, and more specifically, it obtains the matching of the rotational speeds of the front wheels and the rear wheels when turning by one brake. The present invention relates to an agricultural four-wheel drive vehicle.

[Conventional technology]

In a four-wheel drive vehicle for agriculture such as a speed sprayer, a one-side brake that brakes only the rear wheel inside the turning direction at the time of turning is used in order to reduce the turning radius as much as possible.

In this case, since a differential gear exists between the left and right rear wheels, when turning with one brake, the rotation speed of the rear wheel without the one brake applied is twice the normal speed. , It is impossible to distribute the number of rotations between the front and rear wheels, and the rear wheel with the one-sided brake is dragged to soil, dig, or pile up the soil to damage the field. In addition to being a cause, it also increases the turning radius.

For a given four-wheel drive vehicle for agriculture, single brake is not used, but when the steering angle exceeds a predetermined range, the speed of the front wheel is doubled by changing the reduction ratio in the transmission, and the front and rear wheels are rotated. The rotational speed difference between and is optimized.

[Problems to be Solved by the Invention]

Making the number of rotations of the front wheels twice as many as that of the rear wheels by the transmission complicates the braking device.

An object of the present invention is to optimize the rotational speed difference between the front wheels and the rear wheels without requiring switching by a transmission, and to eliminate the troublesomeness of brake selection at the time of turning by using one brake.

JP-A-62-198521 discloses that in a four-wheel drive vehicle including a passenger car, the rotational power from the engine is distributed to diagonally driven wheels. However, in this four-wheel drive vehicle, not only the one-side brake is not used, but there is no intention of using the one-side brake, and it does not serve as the basis of the technology for solving the harmful effect elimination by the one-side brake.

[Means for Solving the Problems]

The present invention will be described using the reference numerals of the drawings corresponding to the embodiments.

The agricultural four-wheel drive vehicle (10) according to the present invention has an engine (38).
And the rotational power from this engine (38) is applied to the left front wheel (1
2) and the first differential gear (48) that distributes and outputs to the right rear wheel (18) and the rotational power from the engine (38) to the right front wheel (14) and the left rear wheel (16). The output second differential gear (50), the left side brake (20) for braking the left rear wheel (16), and the left side brake (20) can be operated independently to brake the right rear wheel (18). The steering angle of the steering wheel (28) is input when the right brake (22), the steering angle detector (32) that detects the steering angle of the steering wheel (28), and the detection signal of this steering angle detector (32) are input. A brake operating portion (36) for operating the left brake (20) or the right brake (22) on the inner side in the turning direction when the predetermined range is exceeded.

[Action]

For example, when turning left by one brake, the left rear wheel (16) on the inner side in the turning direction is braked by the left brake (20) and becomes substantially locked. Rotational power from the engine (38) is supplied to the left front wheel (12) and the right rear wheel (18) by the first differential gear (48) and the second differential gear (50), and to the right front wheel (14). And the left rear wheel (16), the right front wheel (14) as a drive wheel on the outer side in the turning direction has a rotation speed of about 2 when traveling straight ahead.
Double the number of rotations and drive. Also, the ground resistance and the first
The rotational speed of the right rear wheel (18) is greater than that of the left rear wheel (16) and the rotational speed of the left front wheel (12) is greater than that of the right rear wheel (18) due to the distribution of rotational power by the differential gear (48) of ) Is smaller than the rotation speed of the right front wheel (14). When the four-wheel drive vehicle for agriculture (10) of the present invention is to be turned with a small turning radius, the operation amount of the steering wheel (28) increases, and the steering angle exceeds a predetermined range. Whether or not the steering angle exceeds a predetermined range is detected by the steering angle detector (32), and when it is detected that the steering angle exceeds the predetermined range, the brake operating unit (36) is located on the inner side in the turning direction. The left-side brake (20) or the right-side brake (22) is operated to put the agricultural four-wheel drive vehicle (10) in the one-side brake state.

〔Example〕

 Hereinafter, the present invention will be described with reference to the embodiments of the drawings.

FIG. 1 shows a speed sprayer 10 equipped with a single brake mechanism.
It is a block diagram of a drive system of. The speed sprayer 10 includes a left front wheel 12, a right front wheel 14, a left rear wheel 16 and a right rear wheel 18 as driving wheels, and a left brake 20 and a right brake 22 brake the left rear wheel 16 and the right rear wheel 18, respectively. The operator independently operates the left brake pedal 24 and the right brake pedal 26 in the driver's seat. The steering wheel 28 is connected to the left front wheel 12 and the right front wheel 14, which also serve as steered wheels, through a steering link 30, and a steering angle detector 32 determines the steering angle of the steering wheel 28 from the displacement of a predetermined portion of the steering link 30. To detect. The relay 34 is a steering angle detector 32.
When the steering angle detector 32 detects that the steering angle of the steering wheel 28 to the left or right exceeds a predetermined value, the steering angle detector 32 indicates that the steering angle exceeds the predetermined value and the turning direction. Send output to actuator 36. The actuator 36 selectively actuates the left brake 20 and the right brake 22 with hydraulic pressure and pressurized air or the like. The rotational power of the engine 38 is sent to the distributor 42 via the manual transmission 40 that is manually operated by the operator in the driver's seat, and the first output shaft 44 and the second output shaft 46 of the distributor 42 output the first power. Of the differential gear 48 and the second differential gear 50 of FIG. The first differential gear 48 and the second differential gear 50 are provided side by side on the left front wheel 12 side and the right front wheel 14 side, respectively, in the front-rear direction of the speed sprayer 10, and extend the output shaft 52 and the output shaft 54 left and right. ing. In the first differential gear 48, the left output shaft 52 also serves as the axle of the left front wheel 12, and the right output shaft 54 is connected to the front end portion of the propeller shaft 56. Also, the second
In the differential gear 50, the left output end 54 is connected to the front end of the propeller shaft 58, and the right output shaft 52
Also serves as the axle of the right front wheel 14. Propeller shaft 56,5
Numerals 8 extend diagonally, intersect each other, and are connected at their rear ends to an axle 62 of the right rear wheel 18 and an axle 60 of the left rear wheel 16, respectively.

FIG. 2 is a structural diagram of the first differential gear 48. The structure of the first differential gear 48 is known per se, and the second differential gear 50 has the same structure as the first differential gear 48, and therefore the description thereof will be omitted. The drive gear 64 is
It consists of a bevel gear and is fixed to the front end of the first output shaft 44,
It meshes with the ring gear 68 of the bevel gear. The pinion shaft 70 is rotatably supported by the differential case 66 so as to be perpendicular to the extending direction of the output shafts 52, 54, and the differential pinion 72 is fixed. The side gears 74, 74 are fixed to the ends of the output shafts 52, 54, respectively, and mesh with the differential pinion 72. Rotation of the first output shaft 44 causes a differential case
66 rotates and the differential pinion 72 rotates in relation to the ratio of the rotational resistances of the output shafts 52, 54, and thus the output shafts 52, 54 have a rotational speed that is inversely proportional to the ratio of their rotational resistances.

The operation of the embodiment will be described.

When operating the single brake manually, use the actuator 36
Is deactivated or deactivated. When turning to the left with one brake, for example, the operator depresses the left brake pedal 24, and the left rear wheel 16 on the inner side in the turning direction is braked by the left brake 20 and becomes substantially locked. Rotational power from the engine 38 passes through a manual transmission 40 and a distributor 42 from a first output shaft 44 and a second output shaft 46 of the distributor 42 to a first differential gear 48 and a second differential gear 50. Transmitted. Then, by the first differential gear 48 and the second differential gear 50, the left front wheel 12 and the right rear wheel 18 and the right front wheel 14 and the left rear wheel are
The right front wheel 14 as the front drive wheel on the outer side in the turning direction travels at a rotation speed that is about twice the rotation speed when traveling straight ahead. Further, due to the ground resistance and the distribution of the rotational power by the first differential gear 48, the rotation speed of the right rear wheel 18 is higher than that of the left rear wheel 16, and the rotation speed of the left front wheel 12 is that of the right rear wheel 18. It is larger than the number and smaller than the rotation number of the right front wheel 14.

When the one-side brake is automatically operated, the actuator 36 is in the operation valid state. When trying to turn the speed sprayer 10 with a small turning radius, the operation amount of the steering wheel 28 increases, and the steering angle exceeds the predetermined range.
The steering angle detector 32 detects the steering angle, and when the steering angle exceeds a predetermined range, a signal indicating that the steering angle exceeds a predetermined value and the turning direction is sent from the relay 34 to the actuator 36.
In this way, the actuator 36 operates the left side brake 20 or the right side brake 22 on the inner side in the turning direction, and the speed player 10 is brought into the one-side brake state. Left front wheel 12, right front axle 14,
The rotation speeds of the left rear wheel 16 and the right rear wheel 18 are automatically adjusted by the first differential gear 48 and the second differential gear 50 to those suitable for turning by one brake, as in the case of manual operation of one brake. Controlled by.

〔The invention's effect〕

In the present invention, the two differential gears are connected so as to distribute the rotational power from the engine to the driving wheels in the diagonal direction, so that the front wheel on the outer side in the turning direction is disengaged when turning using one brake. It is possible to rotate at about twice the number of revolutions when turning, it is possible to optimize the difference in the number of drive wheels in an agricultural four-wheel drive vehicle as a whole, and it is possible to roughen the soil in one-brake turning. If the steering angle of the steering wheel is detected by the steering angle detector and a small turning radius can be obtained by using the single brake, it is possible to suppress the turning radius appropriately and reduce the turning radius appropriately. The inner drive rear wheel is automatically put into a braking state. This saves the operator the trouble of selecting the brake on the inner side in the turning direction, and makes the operation simple and accurate.

[Brief description of drawings]

The drawings relate to an embodiment of the present invention. FIG. 1 is a configuration diagram of a drive system of a speed sprayer having a one-side brake mechanism, and FIG.
The figure is a structural diagram of the first differential gear. 10 ... Speed sprayer (four-wheel drive for agriculture), 12 ...
… Left front wheel, 14 …… Right front wheel, 16 …… Left rear wheel, 18 …… Rear rear wheel, 20 …… Left brake, 22 …… Right brake, 28 ……
Steering wheel, 32 …… Steering angle detector, 36 …… Actuator (brake operation part), 38 …… Engine, 48
...... First differential gear, 50 …… Second differential gear.

Claims (1)

[Claims] Claim: What is claimed is: 1. An engine (38) and a first differential gear (48) for distributing and outputting rotational power from the engine (38) to a left front wheel (12) and a right rear wheel (18).
The rotary power from the engine (38) to the right front wheel (1
4) and a second differential gear (50) that distributes and outputs the left rear wheel (16), a left brake (20) that brakes the left rear wheel (16), and the left brake (20)
And a steering angle detector (32) for detecting the steering angle of the steering wheel (28), a right side brake (22) for braking the right side rear wheel (18), and a steering angle detector ( If a steering angle of the steering wheel (28) exceeds a predetermined range when the detection signal of (32) is input, a brake operation section (36) for activating the left brake (20) or the right brake (22) inside the turning direction is provided. A four-wheel drive vehicle for agriculture characterized by